Alarm System, Based On The Detection Of Parasitic Transmission

At present, there are two major methods of data transmission, wire and wireless, in depot test and monitor system of PLA, but neither is ideal, e.g. high-cost, long work period and hard to maintain, etc. Parasitic transmission is advanced to replace traditional methods, wire and wireless, in this paper, and a sets of system is designed and produced which is used for temperature-humidity testing and alarm giving in depot of PLA. Parasitic transmission is derived from wave carrier, attenuation and disturb are two major trouble in Parasitic transmission which are more extrude in low-Voltage power line. Attenuation and disturbance in parasitic transmission are analyzed in this paper. Microcontroller and parasitic transmission technique are used together in this system, and a master-slave communication web is created to transmit data with the chip AT89C5 1 and AT89C205 1 in the core. Low-Voltage power line and telephone line are borrowed to transmit data. Hardware and software in microcontroller are fully used in this system, the trouble of disturbance and the trouble of conflict when some depots are alarming simultaneously is basic resolved. Testing suggest that the result of communication is rather satisfactory.